Changes in the Hematology Parameters of Freshwater Fish Channa striatus Expos...BRNSS Publication Hub
In the present study was sublethal concentrations of propargite pesticide administered to freshwater fish C. striatus for 96 hours propargite exposure is 0.34 parts per million (ppm) based on the period of (0.034ppm), (1.02ppm), 15 and 30 days about significantly (P > 0.05) in hematological parameters alterations was recorded. The hematological analysis showed significant (P > 0.05) reduction in red blood cell count, hemoglobin value, packed cell volume, mean corpuscular hemoglobin (MCH), MCH concentration, and mean corpuscular volume. The parameters such as total white blood cells increased when induced toxic content. The present study indicated marked changes in the blood of C. striatus after exposure to propargite pesticide.
Toxicological Effect of Effluents from Indomie Plc on Some Biochemical Parame...IOSR Journals
1) The study examined the effect of effluent from an Indomie food company on biochemical parameters of fish in the New Calabar River in Nigeria.
2) Fish and water samples were collected from four stations - a non-point control station, the effluent discharge point, and stations 10m upstream and downstream.
3) Analysis found higher levels of potassium, sodium, urea and creatinine in the blood, gills, liver and muscles of fish sampled closest to the discharge point, indicating pollution has the greatest effect near the source of the effluent.
Vibrio Species Isolated from Farmed Fish in Basra City in IraqDrNajimRKhamees
This study was carried out to investigate the occurrence of potentially pathogenic species of Vibrio in seven types of fish sampled from fish farms located in different districts in Basra governorate, Iraq. A total of 153 live fishes was collected from fish farms during the period January till May 2016. Bacteria were isolated using selective medium thiosulfate citrate bile sucrose salt agar. Presumptive Vibrio colonies were identified using the VITEK 2 system and selected biochemical tests. In the present study V. alginolyticus (24 of 60) was the predominant species, followed by V. cholerae (10 of 60), V. furnisii (10 of 60), V. diazotrophicus (7 of 60), V. gazogenes (5 of 60) and V. costicola (4 of 60). The signs of vibriosis appeared in three
types of fish, including Cyprinus carpio, Coptodon zillii and Planiliza subviridis in spite of the using Oxytetracycline in most fish farms. The results of the present study demonstrated the presence of pathogenic Vibrio species nearly in all fish farms. So the farm owners should be concerned about the presence of these pathogenic bacteria which also contributes to human health risk and should adopt best management practices for responsible aquaculture to ensure the quality of fish.
Heavy Metals in organs and endoparasites of Oreochromisniloticus, Sediment an...iosrjce
IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) multidisciplinary peer-reviewed Journal with reputable academics and experts as board member. IOSR-JESTFT is designed for the prompt publication of peer-reviewed articles in all areas of subject. The journal articles will be accessed freely online.
This document discusses low impact fishing techniques and modifications that can be made to existing techniques in the Baltic Sea. It provides details on various active and passive fishing gears used in the Baltic Sea, including bottom trawls, Danish seines, pelagic trawls, purse seine nets, gill nets, trap nets, longlines and pots. For each gear, it discusses the effects on target species selectivity, bycatch, habitat impacts, vulnerable species, and fuel efficiency. It also proposes technical improvements that could be made to fishing gears to reduce environmental impacts and make fisheries more sustainable.
Mycological flora of Clarias gariepinus exposed to an oilfield wastewater in ...Innspub Net
The Mycological flora of Clarias gariepinus exposed to sub-lethal concentrations of an oilfield wastewater were investigated. The concentrations included 0% (control), 10, 20, 30, 40, 50 and 60% respectively. Physico-chemistry and mycoflora of wastewater and tissues of Clarias gariepinus were
determined using standard methods. Mean values obtained were; temperature 25.93±6.7oC, pH 7.73±0.31, turbidity 40.33±1.53 NTU, salinity 6584±137mg/l, conductivity 15200±1058.68μs/cm, total dissolved solids 8436.33±501.68 mg/l, total suspended solids 4.67±0.58mg/l, alkalinity
1296.33±2168mg/l, dissolved oxygen 1.83±0.38mg/l, biochemical oxygen demand 1.3±0.7mg/l and Total hydrocarbon 40.54±50mg/l. Temperature, DO, BOD and THC were below allowable FEPA limits while all other components were higher. Mean counts of total fungi and petroleum degraders in the oilfield wastewater were 4.7±0.46x106 sfu/ml and 59.7±25.7% respectively. Fungal counts in the
tissues of Clarias ranged from 0.20±0.00 x 104sfu/g to 3.00±0.00 x 104sfu/g (skin), 0.48±0.05 x 104sfu/g to 7.25±0.96 x 104sfu/g (gills), and 1.13±0.15 x 104sfu/g to 5.75±0.50 x 104sfu/g (intestine). The intestine had higher fungal counts, but the gills recorded the highest at 10%
concentration. Fungi isolated included; Aspergillus fumigatus (46.43%), Aspergillus niger (100%), Fusarium spp. (100%), Mucor spp. (24.99%), Penicillium spp. (57.14%), Rhizopus spp. (32.13%) and Saccharomyces spp. (34.3%). All except Saccharomyces spp were isolated from oilfield wastewater.
Aspergillus spp. Penicillium spp, Mucor and Rhizopus are considered normal flora, but can still cause infection which may result in the mortality of the fish and eventually economic loss to the aquarium fish industry. Proper treatment of oilfield wastewater prior to discharge into the recipient water body is
advocated to reduce ecotoxicological problems. Get more articles at: http://www.innspub.net/volume-3-number-1-july-2015-ijmm/
Organochlorine pesticides were measured across the food web of Lagos Lagoon, Nigeria. Sediment had the highest total concentrations of organochlorine pesticides, ranging from 0.00 to 1673.57 μg/kg. Certain species, such as the shrimp Melicertus keraturus, accumulated high levels of pesticides, posing health risks to humans. Pesticide concentrations in biota were influenced by habitat, feeding habits, and lipid composition. Continued monitoring is needed to assess and address pesticide pollution in the lagoon.
Wan Marlin Rohalin, Nadzifah Yaakub and Najwa Mohd Fazdil. “Level of Zinc and Lead in Freshwater Fishes in Balok River, Pahang, Malaysia” United International Journal for Research & Technology (UIJRT) 1.1 (2019): 44-48.
Changes in the Hematology Parameters of Freshwater Fish Channa striatus Expos...BRNSS Publication Hub
In the present study was sublethal concentrations of propargite pesticide administered to freshwater fish C. striatus for 96 hours propargite exposure is 0.34 parts per million (ppm) based on the period of (0.034ppm), (1.02ppm), 15 and 30 days about significantly (P > 0.05) in hematological parameters alterations was recorded. The hematological analysis showed significant (P > 0.05) reduction in red blood cell count, hemoglobin value, packed cell volume, mean corpuscular hemoglobin (MCH), MCH concentration, and mean corpuscular volume. The parameters such as total white blood cells increased when induced toxic content. The present study indicated marked changes in the blood of C. striatus after exposure to propargite pesticide.
Toxicological Effect of Effluents from Indomie Plc on Some Biochemical Parame...IOSR Journals
1) The study examined the effect of effluent from an Indomie food company on biochemical parameters of fish in the New Calabar River in Nigeria.
2) Fish and water samples were collected from four stations - a non-point control station, the effluent discharge point, and stations 10m upstream and downstream.
3) Analysis found higher levels of potassium, sodium, urea and creatinine in the blood, gills, liver and muscles of fish sampled closest to the discharge point, indicating pollution has the greatest effect near the source of the effluent.
Vibrio Species Isolated from Farmed Fish in Basra City in IraqDrNajimRKhamees
This study was carried out to investigate the occurrence of potentially pathogenic species of Vibrio in seven types of fish sampled from fish farms located in different districts in Basra governorate, Iraq. A total of 153 live fishes was collected from fish farms during the period January till May 2016. Bacteria were isolated using selective medium thiosulfate citrate bile sucrose salt agar. Presumptive Vibrio colonies were identified using the VITEK 2 system and selected biochemical tests. In the present study V. alginolyticus (24 of 60) was the predominant species, followed by V. cholerae (10 of 60), V. furnisii (10 of 60), V. diazotrophicus (7 of 60), V. gazogenes (5 of 60) and V. costicola (4 of 60). The signs of vibriosis appeared in three
types of fish, including Cyprinus carpio, Coptodon zillii and Planiliza subviridis in spite of the using Oxytetracycline in most fish farms. The results of the present study demonstrated the presence of pathogenic Vibrio species nearly in all fish farms. So the farm owners should be concerned about the presence of these pathogenic bacteria which also contributes to human health risk and should adopt best management practices for responsible aquaculture to ensure the quality of fish.
Heavy Metals in organs and endoparasites of Oreochromisniloticus, Sediment an...iosrjce
IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) multidisciplinary peer-reviewed Journal with reputable academics and experts as board member. IOSR-JESTFT is designed for the prompt publication of peer-reviewed articles in all areas of subject. The journal articles will be accessed freely online.
This document discusses low impact fishing techniques and modifications that can be made to existing techniques in the Baltic Sea. It provides details on various active and passive fishing gears used in the Baltic Sea, including bottom trawls, Danish seines, pelagic trawls, purse seine nets, gill nets, trap nets, longlines and pots. For each gear, it discusses the effects on target species selectivity, bycatch, habitat impacts, vulnerable species, and fuel efficiency. It also proposes technical improvements that could be made to fishing gears to reduce environmental impacts and make fisheries more sustainable.
Mycological flora of Clarias gariepinus exposed to an oilfield wastewater in ...Innspub Net
The Mycological flora of Clarias gariepinus exposed to sub-lethal concentrations of an oilfield wastewater were investigated. The concentrations included 0% (control), 10, 20, 30, 40, 50 and 60% respectively. Physico-chemistry and mycoflora of wastewater and tissues of Clarias gariepinus were
determined using standard methods. Mean values obtained were; temperature 25.93±6.7oC, pH 7.73±0.31, turbidity 40.33±1.53 NTU, salinity 6584±137mg/l, conductivity 15200±1058.68μs/cm, total dissolved solids 8436.33±501.68 mg/l, total suspended solids 4.67±0.58mg/l, alkalinity
1296.33±2168mg/l, dissolved oxygen 1.83±0.38mg/l, biochemical oxygen demand 1.3±0.7mg/l and Total hydrocarbon 40.54±50mg/l. Temperature, DO, BOD and THC were below allowable FEPA limits while all other components were higher. Mean counts of total fungi and petroleum degraders in the oilfield wastewater were 4.7±0.46x106 sfu/ml and 59.7±25.7% respectively. Fungal counts in the
tissues of Clarias ranged from 0.20±0.00 x 104sfu/g to 3.00±0.00 x 104sfu/g (skin), 0.48±0.05 x 104sfu/g to 7.25±0.96 x 104sfu/g (gills), and 1.13±0.15 x 104sfu/g to 5.75±0.50 x 104sfu/g (intestine). The intestine had higher fungal counts, but the gills recorded the highest at 10%
concentration. Fungi isolated included; Aspergillus fumigatus (46.43%), Aspergillus niger (100%), Fusarium spp. (100%), Mucor spp. (24.99%), Penicillium spp. (57.14%), Rhizopus spp. (32.13%) and Saccharomyces spp. (34.3%). All except Saccharomyces spp were isolated from oilfield wastewater.
Aspergillus spp. Penicillium spp, Mucor and Rhizopus are considered normal flora, but can still cause infection which may result in the mortality of the fish and eventually economic loss to the aquarium fish industry. Proper treatment of oilfield wastewater prior to discharge into the recipient water body is
advocated to reduce ecotoxicological problems. Get more articles at: http://www.innspub.net/volume-3-number-1-july-2015-ijmm/
Organochlorine pesticides were measured across the food web of Lagos Lagoon, Nigeria. Sediment had the highest total concentrations of organochlorine pesticides, ranging from 0.00 to 1673.57 μg/kg. Certain species, such as the shrimp Melicertus keraturus, accumulated high levels of pesticides, posing health risks to humans. Pesticide concentrations in biota were influenced by habitat, feeding habits, and lipid composition. Continued monitoring is needed to assess and address pesticide pollution in the lagoon.
Wan Marlin Rohalin, Nadzifah Yaakub and Najwa Mohd Fazdil. “Level of Zinc and Lead in Freshwater Fishes in Balok River, Pahang, Malaysia” United International Journal for Research & Technology (UIJRT) 1.1 (2019): 44-48.
Assessment of polycyclic aromatic hydrocarbons (pa hs) levelsAlexander Decker
This study assessed polycyclic aromatic hydrocarbon (PAH) levels in two commercially important fish species, Tilapia queneesis and Liza falcipinis, collected from three coastal areas in Ogoniland, Nigeria that have been polluted by crude oil. PAH concentrations ranged from below detection limits to 120 μg/kg wet weight in T. queneesis and 78.6 μg/kg wet weight in L. falcipinis. High molecular weight PAHs predominated over low molecular weight PAHs. With the exception of some samples, benzo[a]pyrene concentrations exceeded recommended limits. Estimated carcinogenic risks from PAH exposure were above screening values, indicating significant health risks from consuming
This study analyzed total petroleum hydrocarbons (TPH) in the commercially sold fish Trachurus trecae purchased from Oliha Market in Benin City, Nigeria over a three month period. Samples of fish liver, gills, muscle and kidney were tested using gas chromatography-mass spectrometry. The results showed mean TPH concentrations of 73.31, 178.82, 30.40 and 64.37 mg/kg in liver, gills, muscles and kidney respectively, with gills having the highest concentration. While muscle TPH levels were lower than other organs, they still exceeded recommended EU limits of 2μg/kg. The study concluded periodic monitoring of TPH in seafood is needed to
The aquaculture industry has developed significantly over recent decades and is, today, one of the fastest-growing food production sectors in the world. One of the most important problems that affect aquaculture is the appearance of infectious diseases. Among bacterial diseases affecting cultured salmonid fish, Bacterial Cold-Water Disease, caused by Flavobacterium psychrophilum, produces high mortality and morbidity and consequently, economical losses worldwide.
Balai Perikanan Budidaya Laut Batam
Alternative strategies for minimizing the detrimental effects of bacterial infection and prevention of diseases in aquaculture are necessary since the ongoing efficacy of antibiotics is proving to be unsustainable. One of the most promising approach is the use of aqua herbal conditioners to stimulate the immune system of fish to allow them to fight off infections. In this study, the protective effect of aqua herbal conditioners produced from, mainly, mangrove and neem plant extracts in marine fish, was tested on Asian Seabass Lates calcarifer and Silver Pompano Trachinotus blochii at 8-10 g of weight size. Challenge tests were performed by immersion with two pathogenic bacteria: Vibrio harveyi and Vibrio parahaemolyticus, at a concentration of 105 cells ml-1 for 60 minutes after 12 h, 24 h and 36 h conditioning treatment. The experimental trial show that after 72 h, commercially available aqua herbal conditioners (AquaHerb) was able to significantly increase the percentage survival of L. calcarifer and T. blochii and reduces their susceptibilityto the V.harveyi and V.parahaemolyticus. Significantly higher leukocytesnumber, monocyte, neutrophil andphagocyticindexwere detected in all conditioning group for Silver Pompano and Asian Seabass. These results suggest that the combination of herbal extracts together with other trace elements contained in AquaHerb were able to act as immunostimulants and appear to improve the immune status and disease resistance of Asian Seabass and Silver Pompano.
Koteshwar Rao Podeti1*, Benarjee G2
Fisheries Research Laboratory, Department of Zoology, Kakatiya University, India
ABSTRACT- The live freshwater Channa fish species were collected from Hasanparthy and Dharmasagar lakes of
Warangal district. The present investigation deals with the haematological variables in C. striatus and C. punctatus
infected by different bacterial pathogens such as A. hydrophila, S. aureus, P. aeruginosa and S. salmonicida. The
considerable variations have been observed in the mean values of blood parameters. Comparison with the control C.
striatus RBC, HB, values in infected fish were decreased by 63.5%, 23%, increase WBC (21%) had shown and in
Differential leucocyte count (DLC) studies in the control fish show that normal percentage range. In case of bacterial
infected fishes had shown drastic reduction of (30.7%) in Neutrophils was observed whereas Monocytes (2.3%) and
Basophils (0.6%) were not varied much a noticeable increase of (1.5%) in eosinophil and (5.4%) in lymphocytes. And in
the C. punctatus HB content, RBCs, percentage of Monocytes and Neutrophils were significantly decreased by (9%),
(55%), (2.4%) and (18%) respectively. WBCs, Lymphocytes, Esinophils and Basophils were found significantly increased
(17%), (5%), (5.8%) and (2.7%) respectively. This was observed in Red spot diseased fishes thus the above results depict
the presence of macrocyticanaemia in the infected fishes.
Key-words- Channa straitus, Staphylococcus aureus, Hasanparthy, DLC, WBCs
Determination of acute toxicity and the effects of sub-acute concentrations o...Nanomedicine Journal (NMJ)
Abstract
Objective(s):
Copper oxidenanoparticles have different industrial applications so it is inevitable that nanoparticulate products finally find their way into aquatic ecosystems. Nevertheless there is little information available about their effects on some of edible fish. The present study aims to determine the acute toxicity and evaluate the effect of two sub-acute concentrations (50 and 70% 96 h LC50) of CuO-NPs on some hematological and biochemical parameters of R. rutilus.
Materials and Methods:
225 healthy specimen of R. rutilus (mean weight 5.52±1.2 g; mean length 6.20±0.2 cm) were transported to the laboratory. In order to prepare the stock solution, CuO-NPs was dispersed in pure water with ultrasonication (50-60 kHz) for 15 min every day before dosing. At first, R. rutilus was exposed to CuO-NPs to determine the lethal concentration (LC50) value. Following acute test, fish were treated with sub-acute concentrations of CuO-NPs (50 and 70% 96 h-LC50 at) with one control group (no CuO-NPs) for a week to determine the changes in the level of some plasma hematological and biochemical parameters.
Results:
The 96 h-LC50 values of CuO-NPs was 2.19±0.003 mg/l. R. rutilus exhibited significantly lower RBC count, Hb and Hct values and a significant increase in the WBC numbers, MCH, MCHC and MCV indices (p<0.05).><0.05).
Conclusion:
These alterations indicate R. rutilus sensitivity to CuO-NPs and changes in blood parameters would be a useful tool for measurement early exposure to CuO nanoparticles.
Assessment of the Plankton Biodiversity,Bay of Bengal, Cox's Bazar, BangladeshAbuMusa51
I am Abu Musa. This is my Internship Presentation. This is for partial fulfillment of the 4th-year final examination of the Department of Fisheries, University of Dhaka. This is based on my findings from one month of research on the Coxs Bazar coast. The research is done in the live feed lab of BFRI Cox's Bazar.
The document summarizes a dissertation proposal that aims to assess mercury distribution and potential health risks in the Grand Bay National Estuarine Research Reserve. The study will measure mercury levels in fish, water, and sediment samples collected from the reserve using cold vapor atomic absorption spectrometry. The results will help inform policies for managing mercury contamination and assess spatial and temporal trends and risks from mercury exposure.
Ecotoxicity & Risk Assessment of Mercury in the Grand Bay National Estuarine Research Reserve:
Profiling Mercury Distribution in the NERR by Cold Vapor Atomic Absorption Spectrometery
This document summarizes a study on the effects of ammonia toxicity on hemoglobin content in the common carp (Cyprinus carpio). The study exposed fish to a sublethal concentration of ammonia for 35 days and measured hemoglobin levels at various time points. It found a biphasic trend, with hemoglobin decreasing from 7 to 35 days, showing a maximum decrease of 15.948% on day 7 and a minimum decrease of 10.204% on day 35. The decreases in hemoglobin may be due to inhibition of aerobic glycolysis from high ammonia levels stressing the fish. In conclusion, ammonia exposure appeared to negatively impact hemoglobin levels in the common carp over the 35-day period.
The document summarizes the potential ecological impacts of the Deepwater Horizon oil spill on Alabama's coastal waters, with a focus on using oysters as an indicator species. It notes that oysters are sessile, filter feeders that accumulate particles and are commonly used in long-term ecological studies. The document also outlines factors that affect the impacts of oil spills, where to look for impacts, how oysters are important ecologically and economically as a harvested species and habitat, and monitoring efforts underway to assess the effects on oyster survival, growth, condition and contamination levels.
This document describes a proposed study to examine the effects of water soluble fractions of Bonny Light crude oil on juvenile African catfish (Clarias gariepinus). The study will involve acute and subacute exposures of juveniles to different concentrations of the oil to determine toxicity levels and effects on hematology and histopathology. Remotely sensed methods using smartphones will be used to analyze blood parameters and examine tissue samples to detect damage. The goal is to evaluate biomarkers and potentially replace routine laboratory methods with remote sensing for monitoring pollutant impacts on fish.
This study aims to evaluate the effects of water soluble fractions of crude oil on the hematology, histopathology, and carbohydrate reserves of Clarias gariepinus juveniles. 750 juveniles were exposed to various concentrations of water soluble fractions of Bonny Light crude oil for 96 hours to determine lethal concentrations and 10 weeks to determine sublethal effects. Results showed a 96-hour LC50 of 109.95 ml/l and safe level of 1.1 ml/l. Lower sublethal concentrations resulted in reductions in white and red blood cells, tissue damage, and changes in carbohydrate reserves in the liver, muscle, and blood. Histopathological examination revealed reversible and irreversible tissue damage depending on exposure
This document summarizes a study that investigated the potential of using bioremediated sewage effluent from Shehzad Town, Islamabad, Pakistan for fish production. Two ponds were used, one with fresh water and one with the treated sewage effluent. Tilapia and common carp were stocked in both ponds. Less than 1% survival was observed in the pond with treated sewage water, while 100% survival occurred in the fresh water pond. Analysis found high levels of ammonical nitrogen, nitrate nitrogen, and chlorides in the treated water, which were the likely cause of fish mortality. Further treatment of the water using the Coontail plant significantly reduced the levels of these compounds and
GONADAL HISTOPATHOLOGY IN ADULT OLIVE BARB Puntius sarana EXPOSED TO ENDOCRIN...Zobayer Rahman
The document summarizes a study on histological alterations in the gonads of olive barb fish (Puntius sarana) exposed to the endocrine disrupting chemical 17α methyltestosterone. Fish were collected from the Surma River and exposed to three treatment levels of the chemical (40, 60, and 90 mg/kg) over 90 days. Water quality parameters were measured monthly. Gonadal tissues were examined histologically at 30, 60, and 90 days. Higher histological alterations including necrosis, atresia and vitelline envelope breakdown were observed at higher treatment levels and longer exposure times, with the most severe effects at 90 days in the 90 mg/kg treatment. The control fish showed no hist
The document provides information about two upcoming training courses offered by the Freshwater Biological Association (FBA):
1. A two-day course on identifying chironomid larvae from July 15-16 taught by Steve Brooks. The course will provide training on chironomid biology, morphology, taxonomy, and identifying British and European species.
2. A two-day course on July 17-18 about the Chironomid Pupal Exuvial Technique taught by Les Ruse. The course will train participants to sample, identify, and analyze chironomid pupal exuviae to assess water quality.
Both courses aim to teach freshwater biodiversity identification and monitoring techniques. Registration details
The document summarizes a study on local water quality and its effects on fish populations in Alum Creek, Ohio. Fish were collected from various sites along the creek and analyzed to determine biodiversity and each species' tolerance to pollution. The results showed that biodiversity actually increased downstream, contrary to the initial hypothesis, and that fish farther downstream were generally more tolerant of pollution as expected. Water quality impacts the types of fish that can survive in different areas of the creek.
Small-scale fisheries face many challenges, including post-harvest losses which can be a significant economic issue. The document discusses factors that influence the spoilage of fish after harvesting, including time, temperature, and handling practices. The main causes of spoilage are biochemical and microbiological changes as the fish's natural defenses stop working after death. Enzymes and bacteria begin to break down proteins and fats in the fish. Proper processing, packaging, storage, and temperature control are important to reduce post-harvest losses and quality deterioration in fish.
A pilot study on effect of copper and cadmium toxicity in Tilapia Mossambicusresearchanimalsciences
Cu and Cd is trace element for most organisms including fish, but above certain limit Cu and Cd will be toxic. The present study was conducted to evaluate the toxic effect of Cu and Cd on Tilapia mossambicus via estimating the acute 96h median lethal concentration (LC50) value. A total 120 number of Tilapia mossambicus fingerlings were subjected to 12 numbers 20-L aquaria. Fish were exposed to 0.0, 2.0, 4.0, 6.0, 8.0 and 10.0mg Cu and Cd/L for 4 days. Each dose was represented by two aquaria. Fish was daily observed and dead fish were removed immediately. The data obtained were evaluated using Behrens-Karber’s Method. The 96 h LC50 value of Cu for Tilapia mossambicus was calculated to be 6.0mg Cu/L with Behrens-Karber’s Method. The 96 h LC50 value of Cd for Tilapia mossambicus was calculated to be 4.8mg Cd/L with Behrens-Karber’s Method. The behavioral changes of Tilapia mossambicus were primarily observed. It could be concluded that Tilapia mossambicus species slightly sensitive to Cu and Cd when compare both metal cadmium is more toxic than copper for the fish species.
Article Citation:
Anushia C, Sampath kumar P and Selva Prabhu A.
A Pilot Study on Effect of Copper and Cadmium Toxicity in Tilapia Mossambicus.
Journal of Research in Animal Sciences (2012) 1(1): 020-027.
Full Text:
http://janimalsciences.com/documents/AS0008.pdf
Antarctica is Earth's southernmost continent located in the Antarctic region, almost entirely south of the Antarctic Circle. About 98% of Antarctica is covered by ice averaging at least 1.6 kilometers thick, making it the coldest, driest, and windiest continent. While there are no permanent human residents, around 1,000-5,000 people reside at research stations across the continent year-round. Only cold-adapted plants and animals like penguins, seals and mosses survive in Antarctica.
This document lists various species found near Grytviken, South Georgia including penguins like Adelie, Chinstrap, Emperior, and Gentoo penguins, seals, albatrosses, Antarctic petrels, whales, fish like Patagonian Toothfish and Mackerel Icefish, and resources extracted from the area such as chromium, iron ore, nickel, platinum, and coal.
Assessment of polycyclic aromatic hydrocarbons (pa hs) levelsAlexander Decker
This study assessed polycyclic aromatic hydrocarbon (PAH) levels in two commercially important fish species, Tilapia queneesis and Liza falcipinis, collected from three coastal areas in Ogoniland, Nigeria that have been polluted by crude oil. PAH concentrations ranged from below detection limits to 120 μg/kg wet weight in T. queneesis and 78.6 μg/kg wet weight in L. falcipinis. High molecular weight PAHs predominated over low molecular weight PAHs. With the exception of some samples, benzo[a]pyrene concentrations exceeded recommended limits. Estimated carcinogenic risks from PAH exposure were above screening values, indicating significant health risks from consuming
This study analyzed total petroleum hydrocarbons (TPH) in the commercially sold fish Trachurus trecae purchased from Oliha Market in Benin City, Nigeria over a three month period. Samples of fish liver, gills, muscle and kidney were tested using gas chromatography-mass spectrometry. The results showed mean TPH concentrations of 73.31, 178.82, 30.40 and 64.37 mg/kg in liver, gills, muscles and kidney respectively, with gills having the highest concentration. While muscle TPH levels were lower than other organs, they still exceeded recommended EU limits of 2μg/kg. The study concluded periodic monitoring of TPH in seafood is needed to
The aquaculture industry has developed significantly over recent decades and is, today, one of the fastest-growing food production sectors in the world. One of the most important problems that affect aquaculture is the appearance of infectious diseases. Among bacterial diseases affecting cultured salmonid fish, Bacterial Cold-Water Disease, caused by Flavobacterium psychrophilum, produces high mortality and morbidity and consequently, economical losses worldwide.
Balai Perikanan Budidaya Laut Batam
Alternative strategies for minimizing the detrimental effects of bacterial infection and prevention of diseases in aquaculture are necessary since the ongoing efficacy of antibiotics is proving to be unsustainable. One of the most promising approach is the use of aqua herbal conditioners to stimulate the immune system of fish to allow them to fight off infections. In this study, the protective effect of aqua herbal conditioners produced from, mainly, mangrove and neem plant extracts in marine fish, was tested on Asian Seabass Lates calcarifer and Silver Pompano Trachinotus blochii at 8-10 g of weight size. Challenge tests were performed by immersion with two pathogenic bacteria: Vibrio harveyi and Vibrio parahaemolyticus, at a concentration of 105 cells ml-1 for 60 minutes after 12 h, 24 h and 36 h conditioning treatment. The experimental trial show that after 72 h, commercially available aqua herbal conditioners (AquaHerb) was able to significantly increase the percentage survival of L. calcarifer and T. blochii and reduces their susceptibilityto the V.harveyi and V.parahaemolyticus. Significantly higher leukocytesnumber, monocyte, neutrophil andphagocyticindexwere detected in all conditioning group for Silver Pompano and Asian Seabass. These results suggest that the combination of herbal extracts together with other trace elements contained in AquaHerb were able to act as immunostimulants and appear to improve the immune status and disease resistance of Asian Seabass and Silver Pompano.
Koteshwar Rao Podeti1*, Benarjee G2
Fisheries Research Laboratory, Department of Zoology, Kakatiya University, India
ABSTRACT- The live freshwater Channa fish species were collected from Hasanparthy and Dharmasagar lakes of
Warangal district. The present investigation deals with the haematological variables in C. striatus and C. punctatus
infected by different bacterial pathogens such as A. hydrophila, S. aureus, P. aeruginosa and S. salmonicida. The
considerable variations have been observed in the mean values of blood parameters. Comparison with the control C.
striatus RBC, HB, values in infected fish were decreased by 63.5%, 23%, increase WBC (21%) had shown and in
Differential leucocyte count (DLC) studies in the control fish show that normal percentage range. In case of bacterial
infected fishes had shown drastic reduction of (30.7%) in Neutrophils was observed whereas Monocytes (2.3%) and
Basophils (0.6%) were not varied much a noticeable increase of (1.5%) in eosinophil and (5.4%) in lymphocytes. And in
the C. punctatus HB content, RBCs, percentage of Monocytes and Neutrophils were significantly decreased by (9%),
(55%), (2.4%) and (18%) respectively. WBCs, Lymphocytes, Esinophils and Basophils were found significantly increased
(17%), (5%), (5.8%) and (2.7%) respectively. This was observed in Red spot diseased fishes thus the above results depict
the presence of macrocyticanaemia in the infected fishes.
Key-words- Channa straitus, Staphylococcus aureus, Hasanparthy, DLC, WBCs
Determination of acute toxicity and the effects of sub-acute concentrations o...Nanomedicine Journal (NMJ)
Abstract
Objective(s):
Copper oxidenanoparticles have different industrial applications so it is inevitable that nanoparticulate products finally find their way into aquatic ecosystems. Nevertheless there is little information available about their effects on some of edible fish. The present study aims to determine the acute toxicity and evaluate the effect of two sub-acute concentrations (50 and 70% 96 h LC50) of CuO-NPs on some hematological and biochemical parameters of R. rutilus.
Materials and Methods:
225 healthy specimen of R. rutilus (mean weight 5.52±1.2 g; mean length 6.20±0.2 cm) were transported to the laboratory. In order to prepare the stock solution, CuO-NPs was dispersed in pure water with ultrasonication (50-60 kHz) for 15 min every day before dosing. At first, R. rutilus was exposed to CuO-NPs to determine the lethal concentration (LC50) value. Following acute test, fish were treated with sub-acute concentrations of CuO-NPs (50 and 70% 96 h-LC50 at) with one control group (no CuO-NPs) for a week to determine the changes in the level of some plasma hematological and biochemical parameters.
Results:
The 96 h-LC50 values of CuO-NPs was 2.19±0.003 mg/l. R. rutilus exhibited significantly lower RBC count, Hb and Hct values and a significant increase in the WBC numbers, MCH, MCHC and MCV indices (p<0.05).><0.05).
Conclusion:
These alterations indicate R. rutilus sensitivity to CuO-NPs and changes in blood parameters would be a useful tool for measurement early exposure to CuO nanoparticles.
Assessment of the Plankton Biodiversity,Bay of Bengal, Cox's Bazar, BangladeshAbuMusa51
I am Abu Musa. This is my Internship Presentation. This is for partial fulfillment of the 4th-year final examination of the Department of Fisheries, University of Dhaka. This is based on my findings from one month of research on the Coxs Bazar coast. The research is done in the live feed lab of BFRI Cox's Bazar.
The document summarizes a dissertation proposal that aims to assess mercury distribution and potential health risks in the Grand Bay National Estuarine Research Reserve. The study will measure mercury levels in fish, water, and sediment samples collected from the reserve using cold vapor atomic absorption spectrometry. The results will help inform policies for managing mercury contamination and assess spatial and temporal trends and risks from mercury exposure.
Ecotoxicity & Risk Assessment of Mercury in the Grand Bay National Estuarine Research Reserve:
Profiling Mercury Distribution in the NERR by Cold Vapor Atomic Absorption Spectrometery
This document summarizes a study on the effects of ammonia toxicity on hemoglobin content in the common carp (Cyprinus carpio). The study exposed fish to a sublethal concentration of ammonia for 35 days and measured hemoglobin levels at various time points. It found a biphasic trend, with hemoglobin decreasing from 7 to 35 days, showing a maximum decrease of 15.948% on day 7 and a minimum decrease of 10.204% on day 35. The decreases in hemoglobin may be due to inhibition of aerobic glycolysis from high ammonia levels stressing the fish. In conclusion, ammonia exposure appeared to negatively impact hemoglobin levels in the common carp over the 35-day period.
The document summarizes the potential ecological impacts of the Deepwater Horizon oil spill on Alabama's coastal waters, with a focus on using oysters as an indicator species. It notes that oysters are sessile, filter feeders that accumulate particles and are commonly used in long-term ecological studies. The document also outlines factors that affect the impacts of oil spills, where to look for impacts, how oysters are important ecologically and economically as a harvested species and habitat, and monitoring efforts underway to assess the effects on oyster survival, growth, condition and contamination levels.
This document describes a proposed study to examine the effects of water soluble fractions of Bonny Light crude oil on juvenile African catfish (Clarias gariepinus). The study will involve acute and subacute exposures of juveniles to different concentrations of the oil to determine toxicity levels and effects on hematology and histopathology. Remotely sensed methods using smartphones will be used to analyze blood parameters and examine tissue samples to detect damage. The goal is to evaluate biomarkers and potentially replace routine laboratory methods with remote sensing for monitoring pollutant impacts on fish.
This study aims to evaluate the effects of water soluble fractions of crude oil on the hematology, histopathology, and carbohydrate reserves of Clarias gariepinus juveniles. 750 juveniles were exposed to various concentrations of water soluble fractions of Bonny Light crude oil for 96 hours to determine lethal concentrations and 10 weeks to determine sublethal effects. Results showed a 96-hour LC50 of 109.95 ml/l and safe level of 1.1 ml/l. Lower sublethal concentrations resulted in reductions in white and red blood cells, tissue damage, and changes in carbohydrate reserves in the liver, muscle, and blood. Histopathological examination revealed reversible and irreversible tissue damage depending on exposure
This document summarizes a study that investigated the potential of using bioremediated sewage effluent from Shehzad Town, Islamabad, Pakistan for fish production. Two ponds were used, one with fresh water and one with the treated sewage effluent. Tilapia and common carp were stocked in both ponds. Less than 1% survival was observed in the pond with treated sewage water, while 100% survival occurred in the fresh water pond. Analysis found high levels of ammonical nitrogen, nitrate nitrogen, and chlorides in the treated water, which were the likely cause of fish mortality. Further treatment of the water using the Coontail plant significantly reduced the levels of these compounds and
GONADAL HISTOPATHOLOGY IN ADULT OLIVE BARB Puntius sarana EXPOSED TO ENDOCRIN...Zobayer Rahman
The document summarizes a study on histological alterations in the gonads of olive barb fish (Puntius sarana) exposed to the endocrine disrupting chemical 17α methyltestosterone. Fish were collected from the Surma River and exposed to three treatment levels of the chemical (40, 60, and 90 mg/kg) over 90 days. Water quality parameters were measured monthly. Gonadal tissues were examined histologically at 30, 60, and 90 days. Higher histological alterations including necrosis, atresia and vitelline envelope breakdown were observed at higher treatment levels and longer exposure times, with the most severe effects at 90 days in the 90 mg/kg treatment. The control fish showed no hist
The document provides information about two upcoming training courses offered by the Freshwater Biological Association (FBA):
1. A two-day course on identifying chironomid larvae from July 15-16 taught by Steve Brooks. The course will provide training on chironomid biology, morphology, taxonomy, and identifying British and European species.
2. A two-day course on July 17-18 about the Chironomid Pupal Exuvial Technique taught by Les Ruse. The course will train participants to sample, identify, and analyze chironomid pupal exuviae to assess water quality.
Both courses aim to teach freshwater biodiversity identification and monitoring techniques. Registration details
The document summarizes a study on local water quality and its effects on fish populations in Alum Creek, Ohio. Fish were collected from various sites along the creek and analyzed to determine biodiversity and each species' tolerance to pollution. The results showed that biodiversity actually increased downstream, contrary to the initial hypothesis, and that fish farther downstream were generally more tolerant of pollution as expected. Water quality impacts the types of fish that can survive in different areas of the creek.
Small-scale fisheries face many challenges, including post-harvest losses which can be a significant economic issue. The document discusses factors that influence the spoilage of fish after harvesting, including time, temperature, and handling practices. The main causes of spoilage are biochemical and microbiological changes as the fish's natural defenses stop working after death. Enzymes and bacteria begin to break down proteins and fats in the fish. Proper processing, packaging, storage, and temperature control are important to reduce post-harvest losses and quality deterioration in fish.
A pilot study on effect of copper and cadmium toxicity in Tilapia Mossambicusresearchanimalsciences
Cu and Cd is trace element for most organisms including fish, but above certain limit Cu and Cd will be toxic. The present study was conducted to evaluate the toxic effect of Cu and Cd on Tilapia mossambicus via estimating the acute 96h median lethal concentration (LC50) value. A total 120 number of Tilapia mossambicus fingerlings were subjected to 12 numbers 20-L aquaria. Fish were exposed to 0.0, 2.0, 4.0, 6.0, 8.0 and 10.0mg Cu and Cd/L for 4 days. Each dose was represented by two aquaria. Fish was daily observed and dead fish were removed immediately. The data obtained were evaluated using Behrens-Karber’s Method. The 96 h LC50 value of Cu for Tilapia mossambicus was calculated to be 6.0mg Cu/L with Behrens-Karber’s Method. The 96 h LC50 value of Cd for Tilapia mossambicus was calculated to be 4.8mg Cd/L with Behrens-Karber’s Method. The behavioral changes of Tilapia mossambicus were primarily observed. It could be concluded that Tilapia mossambicus species slightly sensitive to Cu and Cd when compare both metal cadmium is more toxic than copper for the fish species.
Article Citation:
Anushia C, Sampath kumar P and Selva Prabhu A.
A Pilot Study on Effect of Copper and Cadmium Toxicity in Tilapia Mossambicus.
Journal of Research in Animal Sciences (2012) 1(1): 020-027.
Full Text:
http://janimalsciences.com/documents/AS0008.pdf
Antarctica is Earth's southernmost continent located in the Antarctic region, almost entirely south of the Antarctic Circle. About 98% of Antarctica is covered by ice averaging at least 1.6 kilometers thick, making it the coldest, driest, and windiest continent. While there are no permanent human residents, around 1,000-5,000 people reside at research stations across the continent year-round. Only cold-adapted plants and animals like penguins, seals and mosses survive in Antarctica.
This document lists various species found near Grytviken, South Georgia including penguins like Adelie, Chinstrap, Emperior, and Gentoo penguins, seals, albatrosses, Antarctic petrels, whales, fish like Patagonian Toothfish and Mackerel Icefish, and resources extracted from the area such as chromium, iron ore, nickel, platinum, and coal.
TINA CALILUNG & JAMIE KELL vs. Ormat, DOJ declines to interveneHonolulu Civil Beat
This court document discusses a civil case from 2014 regarding various legal motions and filings. It provides details on the case number, dates of filings, involved parties, and orders from the presiding judge. The judge denied the plaintiff's motion and granted the defendant's motion, dismissing one of the claims in the lawsuit.
A poll of 780 registered voters in Hawaii found 62% supported and 26% opposed proposed legislation to create medical marijuana dispensaries in each county. 35% thought Hawaii should legalize recreational marijuana use while 59% were opposed. Support for dispensaries was higher among men, younger age groups, Caucasians, liberals, Democrats, and those with higher incomes. Support for recreational use was higher among males, younger groups, Caucasians, liberals, Democrats, and higher incomes.
The Special Committee was tasked with investigating a challenge to Speaker Emeritus Say's qualifications to hold office as the representative of the Twentieth Representative District. The Committee reviewed documents submitted by petitioners challenging Say's residency and Say's counsel responding to those challenges. The Committee then held a public hearing where petitioners' counsel and Say's counsel each made a 20-minute statement and answered Committee questions. The Committee was now obligated to write a report with its findings and recommendations to submit to the full House.
Representative Beth Fukumoto Chang gave the opening remarks for the 2015 legislative session as the House Minority Leader. She thanked her family, constituents, and staff for their support. She stated that the Minority Party is committed to creating a government that meets the needs of everyday citizens and addressing key issues like jobs, healthcare, cost of living, and government transparency. She asked that the majority listen to minority views, as diversity of thought can lead to stronger legislation that improves people's lives and gives them faith in their government.
Food Myths are common and sometimes entertaining . It was probably your mother who told you that you must not believe everything you read .Food Myths are often ridiculous "Urban Myths " driven by social media - Dominated by lifestyle nutritionists - whom differ from Registered Nutritionist
Evaluation of the Accumulation of Ethidium, Malathion, Trifluralin, Dichloro...BRNSSPublicationHubI
This study investigated the accumulation of 5 toxins - ethidium, malathion, trifluralin, DDT, and DDE - in the muscle tissue of 5 fish species from 3 areas of Anzali wetland in Iran. Gas chromatography was used to measure levels of the toxins. The study found that levels of DDT, DDE, ethidium and trifluralin did not differ significantly between the 3 areas. Ethidium and malathion levels were highest in fish and did not differ significantly. All 5 toxins were found to be below standards set by the World Health Organization, indicating they do not pose a health risk to consumers.
Laguna Lake Health Risk Assesment ACTA carcinogenic arsenic_released_feb2015Berean Guide
This document summarizes a study that assessed the carcinogenic health risks of arsenic in five commercially important fish species from Laguna de Bay in the Philippines. The study collected fish samples from eight sites around the lake during both dry and wet seasons. Arsenic levels were measured in the fish to determine if consumption poses health risks to humans. The goal was to understand both risks and benefits of eating these fish regularly from the lake to help inform public health recommendations.
Humankind has not woven the web of life.
We are but one thread within it.
Whatever we do to the web, we do to ourselves.
All things are bound together.
All things connect.
~ Chief Seattle
Impacts from the Deepwater Horizon Oil Spill on Gulf of Mexico FisheriesChristine Hale
The document summarizes research on the impacts of the 2010 Deepwater Horizon oil spill on Gulf of Mexico fisheries. It discusses how the spill may have negatively affected individual fish through exposure to oil and dispersants, but that population- and community-level impacts have been less clear. It also notes several factors that influence the ability to determine the spill's effects, such as previous oil exposure in some areas, fishing closures during the spill, and the need for long-term studies.
This study examined the effects of subchronic dietary exposure to cadmium, methylmercury, and polychlorinated biphenyls on hematological parameters in the tropical fish species Rastrineobola argentea. 180 fish were exposed to feeds containing low doses of these contaminants over 45 days. Blood samples showed that red blood cell count, hemoglobin concentration, hematocrit, and white blood cell counts significantly decreased in the exposed groups compared to controls. Mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration significantly increased in the exposed groups. The results indicate that subchronic exposure to these contaminants can be detected through changes in hematological biomarkers in R. argentea,
Standard water quality requirements and management strategies for fish farmin...eSAT Journals
A study on standard water quality requirements and management strategies suitable for fish farming is presented. The water quality criteria studied based on physical, chemical and biological properties of water include temperature, turbidity, total suspended solids (TSS), total dissolved solid (TDS), nitrate- nitrogen, pH, biochemical oxygen demand (BOD) and total hardness. Water samples from Otamiri River in Imo state, Nigeria, were analyzed based on the afore-mentioned criteria to assess its suitability as a source of water for fish farming. The results of the analysis compared with international standards revealed that the river temperature of 26.90C, nitrate-nitrogen value of 0.015 mg/l and total suspended solids of 18.60 mg/l fall within the acceptable range for fish farming. However, the pH of 5.82, total hardness of 5.8 mg/l, total dissolved solids of 13.60 mg/l and biochemical oxygen demand of 0.6 mg/l all differed slightly from the standard recommended values. This study will aid fish farmers on the necessary treatment needed to effectively use water from this source for fish farming.
Keywords: Water quality criteria, Otamiri River, biochemical oxygen demand, total suspended and total dissolved solids.
Information about composition of deep-sea edible part might raise their value as table food. Proximate composition of few fin fish species from North Atlantic, eastern North Pacific has been reported. No literature is available for either fin fish or shell fish from deep waters off the Indian EEZ.
Aquaculture products can harbor pathogenic bacteria which are part of the natural microflora of the environment. A study was conducted aiming at the isolation of human pathogenic bacteria in gills, intestines, mouth and the skin of apparently healthy fish, Tilapia rendali and Oreochromic mossambicus, from the Fletcher dam. Bacterial pathogens associated with fish can be transmitted to human beings from fish used as food or by handling the fish causing human diseases. Differentiation and characterization of various isolates was based on their growth characteristics on specific culture media (biochemical and gram staining reactions). The following human pathogenic bacteria were isolated Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Vibrio cholerae, Shigella dysenteriae and Enterococcus faecalis. All the bacterial species which were isolated from the fish were also present in the initial water samples collected. The isolation of enteric bacteria in fish serves as indicator organisms of faecal contamination and or water pollution. Their presence also represents a potential hazard to humans. The mean bacterial load of the isolates was found to be markedly higher than the recommended public health and standard value of 5.0 x 106 CFU/ml which has been adopted by many countries.
This document discusses trends in culinary tourism related to seafood. It begins by introducing the health benefits and contamination concerns regarding seafood consumption. It then categorizes common types of seafood into three groups: molluscs, crustaceans, and fish. Specific examples are provided for each group. The document also discusses trends in the seafood market, including segmentation by product and region. The leading seafood vendors globally are identified. Finally, the top 10 seafood restaurants in the world are listed, along with some popular seafood dishes that represent current culinary trends.
Microflora of fresh and smoke dried fish in yenagoaalkhwarizmi1968
This document analyzed the microflora of fresh and smoke-dried fish sold in markets in Yenagoa, Nigeria. Bacterial counts for fresh fish ranged from 4.0 x 108 to 2.3 x 1010 cfu/g, while fungal counts ranged from 1.8 x 104 to 7.0 x 104 cfu/g. Bacterial and fungal counts were lower for smoked fish. Twelve bacterial genera were isolated from fresh fish and thirteen from smoked fish. Bacillus was the most common, comprising 50% of fresh fish isolates and 58.8% of smoked fish isolates. Seven fungal genera were isolated from fresh fish and three from smoked fish. Aspergillus and Penicillium
The document provides guidance on performing necropsies for fish. It emphasizes that a complete history and environmental assessment are crucial, as most fish health issues relate to water quality and husbandry. A necropsy examines external features, internal organs, and tissues under a microscope to identify parasites, bacteria, and other pathogens. Care must be taken in sample selection and handling due to fish's delicate tissues and rapid decomposition after death. Basic fish anatomy is reviewed to aid veterinarians in working with diverse species.
DOI: 10.21276/ijlssr.2016.2.4.10
bio-indicators. The present study is focused on the effective use of L. rohita, an economically significant carp as a
bio-indicator of zinc pollution through its several physiological, histopathological biomarkers. Primarily, acute toxicity
test is performed in which the carp fingerlings are exposed to different concentrations (10, 20, 40, 80, 160, 320 ppm) of
zinc sulphate. 96 hour LC50 value is determined to be 100 ppm. It is taken as lethal concentration and the fishes are
exposed to it for a period of 96 hours during which wide range of behavioural abnormalities are evidenced like general
hyperactivity, surfacing activity, hyper-opercular activity, and erratic swimming pattern. It is followed by loss of balance
and convolutions. One fifth of the lethal concentration is taken (i.e., 10 ppm) as sub-lethal concentration and fishes are
exposed to it for a period of 15 days during which growth, behaviour, oxygen consumption, histopathology, hematology
and genotoxicity are studied. Negative growth performance is observed with insignificant length increment up to 0.24 %
and significant weight reduction up to -2.38 %. Wide range of behavioural abnormalities are evidenced which includes,
erratic swimming, hyperactivity, surfacing activity and depression in appetite. Besides, general body discolouration and
haemorrhage are observed as well. Rate of oxygen consumption showed a time dependant decrease which ranged up to
-49.10%. Gills of the fishes are shown to have conspicuous histopathological alterations like lamellar necrosis, lamellar
fusion, lamellar erosion, epithelial lifting and epithelial swelling. Key-words- Bioindicator, L. rohita, Zinc sulphate, Growth, Behaviour, Oxygen Consumption, Histopathology
exploitation of living resources in Antarctica example of competition between the exploiters to be first in obtaining the maximum profit from living resources.
Background: Infectious diseases cause significant production losses in aquaculture every year. Since the gut
microbiota plays an essential role in regulating the host immune system, health and physiology, altered gut
microbiota compositions are often associated with a diseased status. However, few studies have examined the
association between disease severity and degree of gut dysbiosis, especially when the gut is not the site of the
primary infection. Moreover, there is a lack of knowledge on whether bath treatment with formalin, a disinfectant
commonly used in aquaculture to treat external infections, might affect the gut microbiome as a consequence of
formalin ingestion. Here we investigate, through 16S rRNA gene metabarcoding, changes in the distal gut
microbiota composition of a captive-reared cohort of 80 Atlantic salmon (Salmo salar L.), in consequence of an
external bacterial skin infection due to a natural outbreak and subsequent formalin treatment.
Results: We identified Tenacibaculum dicentrarchi as the causative disease pathogen and we show that the distal
gut of diseased salmon presented a different composition from that of healthy individuals. A new, yet undescribed,
Mycoplasma genus characterized the gut of healthy salmon, while in the sick fish we observed an increase in terms
of relative abundance of Aliivibrio sp., a strain regarded as opportunistic. We also noticed a positive correlation
between fish weight and Mycoplasma sp. relative abundance, potentially indicating a beneficial effect for its host.
Moreover, we observed that the gut microbiota of fish treated with formalin was more similar to those of sick fish
than healthy ones.
Conclusions: We conclude that external Tenacibaculum infections have the potential of indirectly affecting the host
gut microbiota. As such, treatment optimization procedures should account for that. Formalin treatment is not an
optimal solution from a holistic perspective, since we observe an altered gut microbiota in the treated fish. We
suggest its coupling with a probiotic treatment aimed at re-establishing a healthy community. Lastly, we have
observed a positive correlation of Mycoplasma sp. with salmon health and weight, therefore we encourage further
investigations towards its potential utilization as a biomarker for monitoring health in salmon and potentially other
farmed fish species.
Keywords: Microbiota, Atlantic salmon, Infectious diseases, Dysbiosis, Tenacibaculosis, Aliivibrio, Mycoplasma,
Biomarkers, Fish growth
Aquaculture in canada and effects of ha bsDhiman GAIN
Importance of Aquaculture in Canada
Fisheries Production
Finfish
Shellfish
Effects of HABs on Salmon production
Effects of HABs on Shellfish production
Effects of Salmon production on HABs
Occurrence of HABs
Eutrophication status in Canada
Hydrography (Lakes Vs Open sea)
Identification of the HA sources
Monitoring programs
Summary and Conclusions
This document summarizes the risks of mercury toxicity from fish consumption, particularly for pregnant women and children. It reviews the pathways of mercury exposure and absorption in humans, sources of methylmercury in fish, and studies investigating neurological effects in children from prenatal mercury exposure. While some studies found adverse effects, others did not, and there is no scientific consensus on a safe level of intake. The document discusses establishing fish advisories in Hawaii to promote limiting consumption of species higher in mercury while maintaining the health benefits of eating fish.
Fish Stock Assessment in the Philippines. Chapter 1GinaGallano
A stock assessment is the process of collecting, analyzing, and reporting demographic information to determine changes in the abundance of fishery stocks in response to fishing and, to the extent possible, predict future trends of stock abundance.
This document summarizes a study that analyzed levels of Escherichia coli and Pseudomonas bacteria in Nile tilapia (Oreochromis niloticus) from Kesses Dam and University of Eldoret Fish Farm in Kenya. Thirty fish samples were collected from each source and tested for the bacteria. Results found significantly higher levels of both bacteria in fish from Kesses Dam compared to the fish farm. Bacterial levels in all fish exceeded recommended food safety standards, posing a health risk to consumers. The presence of bacteria is likely due to environmental pollution of the dam and farm waters.
This presentation introduces the concept of sustainable fishing and provides different organizations that also are being sustainably conscious about fishing. They even present how this is done in Alaska and in Hilo.
Similar to PLOS ONE article on UH sea bass study (20)
Gov. Ige sent a letter to California Congresswoman Anna Eshoo in response to her August 2020 request for information about Hawaii's pandemic response.
https://www.civilbeat.org/2020/08/california-congresswoman-wants-answers-on-hawaiis-virus-response-effort/
Audit of the Department of the Honolulu Prosecuting Attorney’s Policies, Proc...Honolulu Civil Beat
This audit was conducted pursuant to Resolution 19-255,
requesting the city auditor to conduct a performance audit of the Honolulu Police Department and the Department of the Prosecuting Attorney’s policies and procedures related to employee misconduct.
Audit of the Honolulu Police Department’s Policies, Procedures, and ControlsHonolulu Civil Beat
The audit objectives were to:
1. Evaluate the effectiveness of HPD’s existing policies, procedures, and controls to identify and respond to complaints or incidents concerning misconduct, retaliation, favoritism, and abuses of power by its management and employees;
2. Evaluate the effectiveness of HPD's management control environment and practices to correct errors and prevent any misconduct, retaliation, favoritism, and abuses of power by its
management and employees; and
3. Make recommendations to improve HPD’s policies, procedures, and controls to minimize and avoid future managerial and operational breakdowns caused by similar misconduct.
The report summarizes use of force incidents by the Honolulu Police Department in 2019. There were 2,354 reported incidents, an increase from 2018. Physical confrontation techniques were used most often (53% of applications). The most common types of incidents requiring force were simple assault (13.4%), mental health cases (13.2%), and miscellaneous public cases (6.7%). Most incidents occurred on Mondays and Saturdays between midnight and 1:59am and involved males aged 34 on average, with the largest proportion being Native Hawaiian/Pacific Islanders (34.5%).
The Office of Health Equity aims to eliminate health disparities in Hawaii. Its vision is for policies and programs to improve the health of underserved groups. Its mission is to increase the capacity of Hawaii's health department and providers to eliminate disparities and improve quality of life. The office identifies disparities, recommends actions to the health director, and coordinates related activities and programs. It works to establish partnerships, identify health needs, develop culturally appropriate interventions, and promote national health objectives. The office's strategic goals are to increase awareness of disparities, strengthen leadership, improve outcomes through social determinants, improve cultural competency, and improve research coordination.
The document calls for unity and collaboration between Native Hawaiian and Pacific Islander communities in Hawaii to address COVID-19. It summarizes that government leaders have failed citizens by being slow to respond to the crisis, not working together effectively, and one in three COVID cases impacting Pacific Islanders. It calls on officials to take stronger, transparent leadership and get resources like contact tracers deployed quickly from Pacific Islander communities. Each day without action will lead to more cases, hospitalizations and deaths. It establishes a response team to improve COVID data and policies for Native Hawaiian and Pacific Islander communities.
This letter from the ACLU of Hawaii to the Honolulu Police Department raises concerns about racial disparities in HPD's enforcement of COVID-19 orders and use of force. It cites data showing Micronesians, Black people, Samoans and those experiencing homelessness were disproportionately arrested. It recommends HPD end aggressive enforcement of minor offenses, racial profiling, and using arrest statistics to measure performance. It also calls for implicit bias training, data collection and transparency regarding police stops, searches and arrests.
This letter from the ACLU of Hawaii to the Honolulu Police Department raises concerns about racial disparities in HPD's enforcement of COVID-19 orders and use of force. It cites data showing Micronesians, Black people, Samoans and those experiencing homelessness were disproportionately arrested. It recommends HPD end aggressive enforcement of minor offenses, racial profiling, and using arrest statistics to measure performance. It also calls for implicit bias training, data collection and transparency regarding police stops, searches and arrests.
This document is a complaint filed in circuit court by Jane Doe against The Rehabilitation Hospital of the Pacific and several individuals. Jane Doe alleges she has experienced discrimination and harassment at her job as a physical therapist at Rehab Hospital based on her sexual orientation. She lists several causes of action against the defendants and is seeking damages for the harm to her career and emotional distress caused by the defendants' actions.
This document provides guidance for large or extended families living together during the COVID-19 pandemic. It recommends designating one or two household members who are not at high risk to run necessary errands. When leaving the house, those individuals should avoid crowds, maintain social distancing, frequently wash hands, avoid touching surfaces, and wear cloth face coverings. The document also provides tips for protecting high-risk household members, children, caring for sick members, isolating the sick, and eating meals together while feeding a sick person.
The Office of Hawaiian Affairs (OHA) requests that the State of Hawaii prioritize collecting and reporting disaggregated data on Native Hawaiians relating to the COVID-19 pandemic. Specifically, OHA asks for disaggregated data from the Departments of Health, Labor and Industrial Relations, and Human Services on topics like COVID-19 cases, unemployment claims, and applications for assistance programs. Disaggregated data is critical to understand how the pandemic is impacting Native Hawaiians and to direct resources most effectively. OHA also requests information on how race data is currently collected by these agencies.
The CLA audit of OHA from 2012-2016 found significant issues in OHA's procurement processes and identified $7.8 million across 32 transactions as potentially fraudulent, wasteful, or abusive. The audit found 85% of transactions reviewed contained issues of noncompliance with policies and laws, while 17% (32 transactions) were flagged as "red flags". Common issues included missing procurement documents, lack of evidence that contractors delivered on obligations, and contracts incorrectly classified as exempt from competitive bidding. The audit provides a roadmap for OHA to investigate potential wrongdoing and implement reforms to address deficiencies.
This document provides a list of pro bono legal service providers for immigration courts in Honolulu, Hawaii, Guam, and the Northern Mariana Islands. However, as of the January 2018 revision date, there are no registered pro bono legal organizations for the immigration courts in Honolulu, Hawaii, Guam, or the Northern Mariana Islands. The document also notes that the Executive Office for Immigration Review maintains this list of qualified pro bono legal service providers as required by regulation, but that it does not endorse or participate in the work of the listed organizations.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
Mayor Kirk Caldwell issued a statement regarding the construction of a multi-purpose field at Waimānalo Bay Beach Park. City Council member Ikaika Anderson had requested halting all grubbing work until September 15 out of concern for the endangered Hawaiian hoary bat. However, the environmental assessment states grubbing of woody plants over 15 feet tall should not occur after June 1 to protect young bats. The city contractor will finish grubbing by the end of May as required. Canceling the contract would cost $300,000 in taxpayer money. Therefore, the city will proceed with completing Phase 1, including a multi-purpose field, play area, and parking lot, for $1.43 million, and will review additional
Youngest c m in India- Pema Khandu BiographyVoterMood
Pema Khandu, born on August 21, 1979, is an Indian politician and the Chief Minister of Arunachal Pradesh. He is the son of former Chief Minister of Arunachal Pradesh, Dorjee Khandu. Pema Khandu assumed office as the Chief Minister in July 2016, making him one of the youngest Chief Ministers in India at that time.
El Puerto de Algeciras continúa un año más como el más eficiente del continente europeo y vuelve a situarse en el “top ten” mundial, según el informe The Container Port Performance Index 2023 (CPPI), elaborado por el Banco Mundial y la consultora S&P Global.
El informe CPPI utiliza dos enfoques metodológicos diferentes para calcular la clasificación del índice: uno administrativo o técnico y otro estadístico, basado en análisis factorial (FA). Según los autores, esta dualidad pretende asegurar una clasificación que refleje con precisión el rendimiento real del puerto, a la vez que sea estadísticamente sólida. En esta edición del informe CPPI 2023, se han empleado los mismos enfoques metodológicos y se ha aplicado un método de agregación de clasificaciones para combinar los resultados de ambos enfoques y obtener una clasificación agregada.
Acolyte Episodes review (TV series) The Acolyte. Learn about the influence of the program on the Star Wars world, as well as new characters and story twists.
Here is Gabe Whitley's response to my defamation lawsuit for him calling me a rapist and perjurer in court documents.
You have to read it to believe it, but after you read it, you won't believe it. And I included eight examples of defamatory statements/
Your Go-To Press Release Newswire for Maximum Visibility and Impact.pdfPressReleasePower4
This downloadable guide explains why press releases are still important for businesses today and the challenges you might face with traditional distribution methods. Learn how [Your Website Name] offers a comprehensive solution for crafting compelling press releases, targeting the right media outlets, and maximizing visibility.
Essential Tools for Modern PR Business .pptxPragencyuk
Discover the essential tools and strategies for modern PR business success. Learn how to craft compelling news releases, leverage press release sites and news wires, stay updated with PR news, and integrate effective PR practices to enhance your brand's visibility and credibility. Elevate your PR efforts with our comprehensive guide.
The Biggest Threat to Western Civilization _ Andy Blumenthal _ The Blogs.pdfAndy (Avraham) Blumenthal
Article in The Times of Israel by Andy Blumenthal: China and Russia are commonly considered the biggest military threats to Western civilization, but I believe that is incorrect. The biggest strategic threat is a terrorist Jihadi Caliphate.
1. Seafood Substitutions Obscure Patterns of Mercury
Contamination in Patagonian Toothfish (Dissostichus
eleginoides) or ‘‘Chilean Sea Bass’’
Peter B. Marko1
*, Holly A. Nance2
, Peter van den Hurk3
1 Department of Biology, University of Hawai’i at Ma¯noa, Honolulu, Hawai’i, United States of America, 2 Indian River State College, Fort Pierce, Florida, United States of
America, 3 Department of Biological Sciences, Clemson University, Clemson, South Carolina, United States of America
Abstract
Seafood mislabeling distorts the true abundance of fish in the sea, defrauds consumers, and can also cause unwanted
exposure to harmful pollutants. By combining genetic data with analyses of total mercury content, we have investigated
how species substitutions and fishery-stock substitutions obscure mercury contamination in Patagonian toothfish
(Dissostichus eleginoides), also known as ‘‘Chilean sea bass’’. Patagonian toothfish show wide variation in mercury
concentrations such that consumers may be exposed to either acceptable or unacceptable levels of mercury depending on
the geographic origins of the fish and the allowable limits of different countries. Most notably, stocks of Patagonian
toothfish in Chile accumulate significantly more mercury than stocks closer to the South Pole, including the South Georgia/
Shag Rocks stock, a fishery certified by the Marine Stewardship Council (MSC) as sustainably fished. Consistent with the
documented geography of mercury contamination, our analysis showed that, on average, retail fish labeled as MSC-certified
Patagonian toothfish had only half the mercury of uncertified fish. However, consideration of genetic data that were
informative about seafood substitutions revealed a complex pattern of contamination hidden from consumers: species
substitutions artificially inflated the expected difference in mercury levels between MSC-certified and uncertified fish
whereas fishery stock substitutions artificially reduced the expected difference in mercury content between MSC-certified
and uncertified fish that were actually D. eleginoides. Among MSC-certified fish that were actually D. eleginoides, several with
exogenous mtDNA haplotypes (i.e., not known from the certified fishery) had mercury concentrations on par with
uncertified fish from Chile. Overall, our analysis of mercury was consistent with inferences from the genetic data about the
geographic origins of the fish, demonstrated the potential negative impact of seafood mislabeling on unwanted mercury
exposure for consumers, and showed that fishery-stock substitutions may expose consumers to significantly greater
mercury concentrations in retail-acquired fish than species substitutions.
Citation: Marko PB, Nance HA, van den Hurk P (2014) Seafood Substitutions Obscure Patterns of Mercury Contamination in Patagonian Toothfish (Dissostichus
eleginoides) or ‘‘Chilean Sea Bass’’. PLoS ONE 9(8): e104140. doi:10.1371/journal.pone.0104140
Editor: Jaymie Meliker, Stony Brook University, Graduate Program in Public Health, United States of America
Received April 17, 2014; Accepted July 6, 2014; Published August 5, 2014
Copyright: ß 2014 Marko et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: The authors confirm that all data underlying the findings are fully available without restriction. All relevant data are within the paper and its
Supporting Information files.
Funding: This work was supported by the National Science Foundation (OCE-0961996). The funder had no role in study design, data collection and analysis,
decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
* Email: pmarko@hawaii.edu
Introduction
Despite the many health benefits of eating fish, most commer-
cially harvested fish are contaminated with mercury [1]. The most
common form of mercury in fish is methylmercury, a neurotoxin
that is especially dangerous to the developing nervous system [2].
Although present in only small quantities in the environment,
mercury accumulates in living organisms. Among fish, accumu-
lation of mercury is prevalent but variable (Fig. 1), primarily due
to differences in trophic level and body size, such that mercury
concentrations tend to be high in larger, longer-lived predatory
fish [3]. Therefore, the amount of fish and the particular species of
fish consumed are considered the most important factors
determining the health risk associated with eating seafood
contaminated with mercury. Consequently, the US Food and
Drug Administration (FDA) advises pregnant and nursing women,
women who may become pregnant, and young children not to eat
species that have mean mercury concentrations near 1.0 ppm
(shark, swordfish, king mackerel, and tilefish), and not to consume
more than 12 ounces per week of other species that have lower
mercury levels.
Less widely appreciated is the fact that variation in mercury
concentration within species can also be large due to the same
causal factors mentioned above [4–6]. As a consequence, even
though the mean mercury level for many species commonly
consumed is only ,0.3 ppm, the range of mercury concentrations
reported from several of these moderately contaminated species
often exceeds import limits (Fig. 1). For example, stocks of the
southern hemisphere Patagonian toothfish (Dissostichus elegi-
noides), or ‘‘Chilean sea bass’’, have been shown to have anywhere
from ,0.15 ppm Hg to .1.0 ppm Hg, often well beyond the
allowable level of 0.5 ppm for imports into New Zealand, Canada,
and Australia, and sometimes greater than the 1.0 ppm limit set by
the European Union and the United States [4,6–10].
PLOS ONE | www.plosone.org 1 August 2014 | Volume 9 | Issue 8 | e104140
2. As with many other species of fish that absorb toxins at a greater
rate than they are eliminated, mercury levels in Patagonian
toothfish are explained in part by body size: the larger, and
presumably the older a fish is, the greater the mercury
concentration [7–10]. However, two recent studies have shown
that mercury accumulation in Patagonian toothfish also has a
strong geographic component. Specifically, fish from higher
latitudes in the Southern Ocean have lower length-normalized
mercury concentrations compared to fish from lower latitudes [9–
10]. In particular, fish from the South Georgia/Shag Rocks
(SGSR) stock have mean mercury levels far below allowable
import levels worldwide, with a mean THg of 0.23 ppm
(SE = 0.01 ppm) compared to fish from nearby Chile, which have
more than three times as much mercury in their tissues (0.73 ppm,
SE = 0.10 ppm) [9]. Mercury levels in fish taken from the SGSR
stock are of particular interest given that several consumer-
education (e.g., Seafood Watch) and seafood sustainability
certification programs (e.g., Marine Stewardship Council or
MSC) consider fish from SGSR populations as eco-friendly
seafood choices, from the perspectives of sustainability and
relatively low by-catch. This combination makes fish from
certified-sustainable southern ocean stocks a potentially attractive
choice for consumers interested in purchasing sustainably
harvested seafood with consistently low levels of mercury.
Accurate labeling of seafood is essential to allow consumers to
reliably choose sustainable fisheries [11–15], but labels may also
serve to protect consumers from unhealthy mercury exposure. For
example, several common species substitutions (i.e., the substitu-
tion of less desirable species for more expensive ones) can result in
unintended high mercury consumption, such as the substitution of
tilefish or king mackerel for grouper [12,17–18]. However, some
fishery-stock substitutions also have the potential to significantly
increase mercury exposure to consumers. For example, Gulf of
Mexico tilefish averages 1.45 ppm Hg, but THg in Atlantic tilefish
is an order of magnitude lower (Fig. 1). Tuna species from the
Atlantic, Pacific and Mediterranean oceans also have significantly
different length-normalized mercury concentrations [4].
Here, we report measured mercury concentrations in Patago-
nian toothfish or ‘‘Chilean sea bass’’ acquired from retail
merchants in the USA. As an indicator for species and fishery-
stock substitutions, we used genetic data from the same samples
that showed 20% of fish labeled as ‘‘Chilean sea bass’’ were not D.
eleginoides (8% of fish sold as MSC-certified Chilean sea bass were
other species whereas 46% of uncertified fish were substitutes), and
among those certified fish positively identified with DNA
techniques as D. eleginoides, 15% had mtDNA haplotypes that
were not present in the previously described MSC-certified stock
[16]. Our analysis of mercury contamination in the genetically-
identified samples shows that the pattern of mercury contamina-
tion is consistent with the interpretation of mislabeling based on
mtDNA haplotype identities, and demonstrates that in addition to
species substitutions, fishery-stock substitutions have the potential
to significantly obscure mercury exposure for consumers.
Methods
Samples
The tissue samples used in this study were a subset of those used
in an analysis of the genetic composition of retail-acquired
‘‘Chilean Sea Bass’’ [16]. All of the samples were purchased
‘‘fresh’’ (i.e., from the thawed seafood counter) from retailers in 10
US states as filets (body wall muscle), which were immediately
stored in 90% ethanol to preserve mtDNA. Samples were acquired
from retailers selling either MSC-certified Chilean sea bass (and
were clearly labeled as such) or from retailers selling fish as
Chilean sea bass, but not as MSC-certified. We measured the total
mercury (THg) concentration in 25 of the MSC-certified fish and
13 of the non-MSC fish.
Total mercury concentration
Samples stored in ethanol were freeze-dried in a VirTis
lyophilizer for 72 h. Of the dried fish tissue, 70–100 mg weighed
samples were digested in sealed Teflon containers with 6 ml nitric
acid in a 1 ppm Au background according to EPA method 3052
[19]. Samples were microwaved at 400 W for 25 min, allowed to
cool and taken up with water. Samples were then analyzed for
total mercury content by ICP-MS according to EPA method 200.8
[20]. For every 5 samples a blank was run, and two reference
samples of oyster tissue were included in the sample series. All
quality control samples fell within acceptable ranges, and the limit
of detection was 0.096 mg/g. To make our dry-weight measure-
ments of THg comparable to wet-weight concentrations in the
literature, we converted our THg measurements into wet-weight
concentrations by dividing by the widely accepted conversion
factor of 3.6 [21].
Statistical Analysis
Because some comparisons involved unequal sample sizes, we
first tested for unequal variances with an F-test and then used t-
tests (either for equal or unequal variances) to examine the data for
differences in THg among groups of samples. P-values were
calculated as one-tailed given the expectation that MSC-certified
fish (which should have originated from SGSR fishery) should
have lower levels of THg than fish that originated from non-
certified fisheries at lower latitudes in the southern hemisphere [9].
Because we performed three t-tests on overlapping subsets of the
data, we considered P-values significant if ,0.05/3 or 0.0167.
Results
Measurements of THg for the retail-acquired Chilean sea bass
in our study varied widely among samples, from a low of 0.07 ppm
to a high of 1.9 ppm. Overall, fish labeled as MSC-certified
Chilean sea bass had less than half the THg of uncertified fish
(Table 1, Fig. 2), a highly significant result (t-test for unequal
variances: t = 22.97, one-tailed p = 0.0050). However, among
only those fish that were genetically verified as D. eleginoides, the
difference in THg between MSC-certified and uncertified fish was
only marginally significant at the 0.05 level and not significantly
different at the 0.0167 level (t-test for unequal variances: t = 2
2.15, one-tailed p = 0.0320).
For MSC-certified fish that were actually D. eleginoides, we
found an uneven distribution of THg contamination: those with
mtDNA haplotypes not known from the MSC-certified fishery
(haplotypes E, F, I, & J) had twice as much mercury (0.63 ppm) as
D. eleginoides with haplotypes known from the South Georgia
stock (0.31 ppm) (Fig. 3; t-test for equal variances: t = 22.87, one-
tailed p = 0.0047). The single fish with haplotype E was unusual
among fish with haplotypes unknown from the certified fishery in
that it had relatively low THg (Fig. 3).
Discussion
Our study of retail acquired Patagonian toothfish or ‘‘Chilean
sea bass’’ demonstrated that both species substitutions and fishery-
stock substitutions obscure a complex pattern of mercury
contamination. First, although fish labeled as MSC-certified
‘‘Chilean sea bass’’ appeared to have significantly lower total
Mercury in Chilean Sea Bass
PLOS ONE | www.plosone.org 2 August 2014 | Volume 9 | Issue 8 | e104140
3. mercury than uncertified fish, consideration of genetically detected
species substitutions (i.e., substitutions of other species for D.
eleginoides) revealed the unexpected result that among fish that
were actually D. eleginoides, the difference in mercury content
between MSC-certified and uncertified fish was small. However,
this unexpected result is explained in part by the finding that the
species that were substituted for MSC-certified fish had relatively
low mercury (mean THg = 0.14 ppm) whereas species substituted
for uncertified fish most commonly had very high mercury (mean
THg = 0.95 ppm). Together, these species substitutions combined
to artificially inflate the difference in mercury levels between all
MSC-certified and uncertified fish.
In contrast, fishery-stock substitutions (substitutions of D.
eleginoides from uncertified stocks for D. eleginoides from certified
Figure 1. Mercury levels in commercial seafood. Data compiled from US FDA, 1990–2010 (http://www.fda.gov/food/
foodborneillnesscontaminants/metals/ucm115644.htm. Accessed 2014 July 14). Dark bars are means, grey are median values. Error bars show the
range of measurements. 1
Gulf of Mexico; 2
South Atlantic; 3
Atlantic. Data from canned and fresh albacore were similar and combined.
doi:10.1371/journal.pone.0104140.g001
Table 1. Total mercury (THg) concentration of fish sold as Chilean sea bass (CSB) with and without MSC labels, indicating their
origin from the certified South Georgia (SG) fishery based on genetic analyses.
Samples N THg (ppm) SD
MSC-labeled fish
i) All fish 25 0.35 0.24
ii) CSB only 22 0.42 0.24
Known SG haplotypes 17 0.31 0.20
Unknown SG haplotypes 5 0.63 0.25
Excluding Heard Island haplotype 4 0.72 0.16
Non-MSC fish
i) All fish 13 0.89 0.60
ii) CSB only 8 0.80 0.56
doi:10.1371/journal.pone.0104140.t001
Mercury in Chilean Sea Bass
PLOS ONE | www.plosone.org 3 August 2014 | Volume 9 | Issue 8 | e104140
4. stocks) also likely contributed to the apparently small difference in
mercury content between MSC-certified and uncertified fish that
were verified genetically as D. eleginoides: several MSC-certified
fish that were genetically verified as D. eleginoides had relatively
high mercury, twice the concentration of most certified fish in our
study (Fig. 3). Given that all of these toothfish with unexpectedly
high mercury also had mtDNA haplotypes unknown from the
certified SGSR fishery, their high mercury content is consistent
with the idea that they did not originate from the certified fishery
[16]. Two of these four fish with exogenous haplotypes had
haplotype F, the dominant haplotype on the Patagonian shelf [22],
where fish are known to accumulate higher mercury levels than
compared to SGSR fish [9]. One fish labeled as MSC-certified
(but which did not possess a haplotype known from the certified
Figure 2. Mercury concentrations among samples of retailed acquired Patagonian toothfish (Dissostichus eleginoides) or Chilean sea
bass (CSB) in this study. Error bars are standard deviations.
doi:10.1371/journal.pone.0104140.g002
Figure 3. Mercury concentrations among mitochondrial DNA haplotypes from MSC-certified retail samples of Patagonian toothfish
(Dissostichus eleginoides) or Chilean sea bass. Error bars are standard deviations.
doi:10.1371/journal.pone.0104140.g003
Mercury in Chilean Sea Bass
PLOS ONE | www.plosone.org 4 August 2014 | Volume 9 | Issue 8 | e104140
5. SGSR fishery) had a haplotype known only from Heard Island
[16]. As with SGSR, Heard Island lies south of the Antarctic Polar
Front, an oceanographic barrier that likely restricts gene flow in D.
eleginoides [22] and might protect the Southern Ocean from
mercury contamination [9]. Consistent with a high-latitude origin,
this putative Heard Island fish had correspondingly low mercury
(0.24 ppm, Fig. 1), outside the 99% confidence interval (0.26–
1.18 ppm) for the four other fish with haplotypes not known from
the certified fishery. Although the Heard Island longline toothfish
fishery is now MSC-certified, it was not certified at the time the
samples in our study were purchased [16].
The potential for species substitutions to cause unintended
mercury exposure for consumers has been described before, but
our study of Patagonian toothfish is novel in that it shows that
fishery-stock substitutions, which are more difficult to detect than
species substitutions, can expose consumers to increased mercury
concentrations in retail-acquired fish. For example, although
species substitutions result in a decrease in mean mercury
concentrations of ,7% (for MSC-certified fish) and an increase
of ,11% (for uncertified fish), fishery-stock substitutions (among
MSC-labeled fish) resulted in an increase in mean mercury of
,100% (Table 1). Because Patagonian toothfish from Chile often
exceed the 1.0 ppm FDA mercury import threshold (and vastly
exceed limits for Canada, New Zealand, and Australia) [9], our
results suggest that in addition to species’ identities, the geographic
origins of fish may be worthy of greater consideration in seafood
consumption studies.
A potential confounding factor in our results may be that we
were not able to correct mercury concentrations with body size of
the sampled fish, because the samples were obtained from fish
filets that were sold at seafood counters in retail stores. Therefore,
an alternative explanation for the unusually high THg of some fish
labeled as having originated from the SGSR stock is that they were
simply very large fish from SGSR. However, given that the MSC-
labeled fish with exogenous mtDNA haplotypes (excluding the fish
with haplotype E, known only from Heard Island) had an average
mercury concentration of 0.72 ppm (Table 1), those fish must
have had average lengths of approximately 160 cm if actually from
SGSR (see Fig. 2 from 9), more than 45 cm longer than any fish
obtained in earlier studies of mercury in SGSR fish [9], a fishery
with a modal catch length of only 75 cm [23]. Furthermore, these
MSC-labeled fish with unusually high mercury levels also had
mtDNA haplotypes not known from the SGSR stock (two of which
are the most common haplotype in Chilean waters) and mercury
levels expected for Chilean fish ranging in size from 75 to 100 cm,
suggesting the mislabeling hypothesis is a better explanation for
MSC-certified fish with unexpectedly high mercury levels.
Although all of our samples were stored in ethanol, our mercury
measurements were consistent with previous measurements from
Patagonian toothfish. For example, we found a mean mercury
level of 0.31 ppm for toothfish with haplotypes known from the
SGSR stock whereas a mean mercury level of 0.23 ppm was
previously reported for frozen fish (i.e., not preserved in ethanol)
sampled from the same fishery [9]. The relative amounts of
mercury between fish from north and south of the Antarctic Polar
Front in the south Atlantic/Southern Ocean were also similar
between our study and earlier work: frozen samples from Chile
had 3.1 times the mercury content of fish from SGSR [9], similar
to a factor of 2.7 in our study in a comparison of uncertified but
genetically identified D. eleginoides (most of which were labeled as
having originated from Chile) to MSC-certified Chilean sea bass
that had mtDNA haplotypes known from the certified fishery.
Therefore, our results are consistent with substantially increased
mercury exposure (twice as much) from fish that did not originate
further south [9–10].
Conclusions
Our study found considerable retail variation in mercury levels
in ‘‘Chilean sea bass’’ that is related to the likely geographic origins
of the fish, but also indicated that species substitutions and fishery-
stock substitutions may obscure apparent levels of mercury among
fish labeled as both MSC-certified and uncertified Patagonian
toothfish. Although on average, MSC-certified fish is a healthier
option with respect to mercury contamination than compared to
uncertified fish, our study showed that fishery-stock substitutions,
can result in a larger proportional increase in mercury consump-
tion than species substitutions for consumers, and that variation in
mercury contamination among fishery stocks may be considered in
future seafood consumption guidelines.
Acknowledgments
K. Barr, B. Wilbur, J. McGuire, B. Sowers, C. Edwards and S. McAlister
collected some of the samples. We thank J. Meliker and two anonymous
reviewers for reading and commenting on the manuscript.
Author Contributions
Conceived and designed the experiments: PM PH HN. Performed the
experiments: PH. Analyzed the data: PH PM. Contributed reagents/
materials/analysis tools: PM PH HN. Contributed to the writing of the
manuscript: PM PH HN. Sample acquisition: HN.
References
1. Hightower JM, Moore D (2002) Mercury Levels in High-End Consumers of
Fish. Environmental Health Perspectives 111: 604–608.
2. Costa LG (1988) Interactions of neurotoxicants with neurotransmitter systems.
Toxicology 49: 359–366.
3. Sackett DK, Cope WG, Rice JA, Aday DD (2013) The influence of fish length
on tissue mercury dynamics: implications for natural resource management and
human health risk. International Journal of Environmental Research on Public
Health. 10(2): 638–659.
4. Sunderland EM (2007). Mercury exposure from domestic and imported
estuarine and marine fish in the U.S. seafood market. Environmental Health
Perspectives, 115(2): 235–42.
5. Piraino MN, Taylor DL (2009) Bioaccumulation and trophic transfer of mercury
in striped bass (Morone saxatilis) and tautog (Tautoga onitis) from the
Narragansett Bay (Rhode Island, USA). Marine Environmental Research, 67:
117–128.
6. Karimi R, Fitzgerald TP, Fisher NS (2012) A Quantitative Synthesis of Mercury
in Commercial Seafood and Implications for Exposure in the United States.
Environmental Health Perspectives 120: 1512–1519.
7. Me´ndez E, Giudice H, Pereira A, Inocente G, Medina D (2001) Preliminary
Report on the Total Mercury Content of Patagonian Toothfish (Dissostichus
eleginoides). Journal of Food Composition and Analysis 14: 547–549.
8. McArthur T, Butler EC V, Jackson GD (2003) Mercury in the marine food
chain in the Southern Ocean at Macquarie Island: an analysis of a top predator,
Patagonian toothfish (Dissostichus eleginoides) and a mid-trophic species, the
warty squid (Moroteuthis ingens). Polar Biology 27: 1–5.
9. Dawson Guynn KD, Peterson MS (2007) Mercury concentrations in the
Patagonian toothfish, Dissostichus eleginoides Smitt 1898, among three distinct
stocks. Polar Biology 31: 269–274.
10. Hanchet SM, Tracey D, Dunn A, Horn P, Smith N (2011) Mercury
concentrations of two toothfish and three of its prey species from the Pacific
sector of the Antarctic. Antarctic Science 24: 34–42.
11. Marko PB, Lee SC, Rice AM, Gramling JM, Fitzhenry TM, et al. (2004)
Mislabelling of a depleted reef fish. Nature 430: 309–310.
12. Lowenstein JH, Amato G, Kolokotronis SO (2009) The real maccoyii:
identifying tuna sushi with DNA barcodes – contrasting characteristic attributes
and genetic distances. PLoS ONE 4: e7866.
Mercury in Chilean Sea Bass
PLOS ONE | www.plosone.org 5 August 2014 | Volume 9 | Issue 8 | e104140
6. 13. von der Heyden S (2009) Why do we need to integrate population genetics into
South African marine protected area planning? African Journal of Marine
Science 31: 263–269.
14. Miller DD, Mariani S (2014) Smoke, poor transparency and mislabeled in the
European cod. Seafood 8: 517–521.
15. Hanner RH, Becker S, Ivanova NV, Steinke D (2011) Fish Barcode of Life and
seafood identification: geographically dispersed case studies reveal systemic
market substitution across Canada Mitochondrial DNA 22: 106–122.
16. Marko PB, Nance HA, Guynn KD (2011) Genetic detection of mislabeled fish
from a certified sustainable fishery. Current Biology 21: R621–2.
17. Mystery fish: the label said red snapper, the said baloney. Consumer Reports
Magazine. Published December 2011. Available: http://www.consumerreports.
org/cro/magazine-archive/2011/december/food/fake-fish/overview/index.
htm. Accessed 2014 July 14.
18. What you need to know about mercury in fish and shellfish. U.S. Food and Drug
Administration. Published March 2004. Available: http://www.fda.gov/food/
foodborneillnesscontaminants/buystoreservesafefood/ucm110591.htm. Ac-
cessed 2014 July 14.
19. Microwave assisted acid digestion of siliceous and organically based matrices.
Method 3052. US-Environmental Protection Agency. Published December
1996. Available: http://www.epa.gov/wastes/hazard/testmethods/sw846/
pdfs/3052.pdf. Accessed 2014 July 14.
20. Determination of trace elements in waters and wastes by Inductive Coupled
Plasma - Mass Spectrometry. Method 200.8. US-Environmental Protection
Agency. Published 1994. Available: http://water.epa.gov/scitech/methods/
cwa/bioindicators/upload/2007_07_10_methods_method_200_8.pdf. Accessed
2014 July 14.
21. Streit B (1998) Bioaccumulation of contaminants in fish. In: Braunbeck T,
Hinton DE, Streit B, editors. Fish Ecotoxicology. Basel: Birkhauser. 353–399.
22. Shaw PW, Arkhipkin AI, Al-Khairulla H (2004) Genetic structuring of
Patagonian toothfish populations in the Southwest Atlantic Ocean: the effect
of the Antarctic Polar Front and deep-water troughs as barriers to genetic
exchange. Molecular Ecology 13: 3293–3303.
23. Hillary RM, Kirkwood GP, Agnew DJ (2006) An Assessment of toothfish in
subarea 48.3 using Casal. CCAMLR Science 13: 65–95.
Mercury in Chilean Sea Bass
PLOS ONE | www.plosone.org 6 August 2014 | Volume 9 | Issue 8 | e104140